Samuel darling



(N0 MQdeL) s. DARLING. METALLIG .TRY SQUARE.

Patented Jan. 17,1882.

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Plan 4' FIG 5.-

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PlEl 7| INVE N TCIRa v. Washington,

. UNITED STATES PATENT Y can.

- SAMUEL DARLING, orPRovmENcE, RHODE ISLAND.

METALLLIC TR -SQUARE.

SPECIFICATION forming part of Letters Patent No. 252,436, dated January 17, 11882,

Application filed September 14, 1881. No model.) I

Be it 'known that I, SAMUEL DARLING, a citizen of the United States, residing at Providence,'in the county of Providence and State of Rhode Island, have invented a new and usefullmprovementin Metallic Try-Squares; and I do hereby declare that thefollowing specifi- To all whom it may concern:

' cation, taken in connection with the accompanying drawings, forming a part of the same, is a full, clear, and exact description thereof.

My improvement relatesto the position of the blade in the stock and the mode of fastening it; and the object of the invention is to produce a try-square of greater accuracy and durability, and one in which the blade can be readily adj usted', removed, repaired, and readjusted, or a' new one substituted; a try-square in which the position of the blade and mode of one end, instead of a slot in the center, wheresquare-blades have heretofore been located; in fastening the blade to the stock with a double bolt, one part of which binds the blade to the side of the stock, while the other part forces the edge of the blade against the shoulder in the stock made by the gain, as shown in the drawin gs, and hereinafter more fully explained; and,

' also, in pressing the edge of the blade against the shoulder in the stock sufficiently to spring the stock slightly, thus producing an elastic or reserve force to keep the edge of the blade firmly against the shoulder in the stock to prevent. any slight yielding ot' the surfaces in con-t tact from loosening the blade. The springing of the stock .(iOl'inch will be sufficient to produce the reserve force needed.

p In the drawings, Figure 1 is a side elevation of a part of a try-square embracing my im provement; Fig. 2, a horizontal section of the same through line w m,- Fig. 3, a side elevation of a larger square, having four common screws in addition to the double bolt; Fig. 4, a side elevation of my improved square put together with ,tained in that way of-t'astening stock together.

tapering screw; .dotted lines in Fig. 2,- an exaggerated view stock.

The letter A represents the joint end of the stock of the try-square; blade; 0, a hollow split bolt; D, screw for expanding bolt 0; E, tapering screw; F, common conical-headed screws; G, notch for screwdriver; H, split in bolt 0; I, enlargement, of the hole in the stock; J, enlargement of the hole in the blade; K, shoulder in thehandle.

My improvement is especially adapted to large squares made of hardened cast-steelfas they can bemade in that form without drawing the temper, which cannot be done when of the crook or spring in the B, the joint end of the the blade is soldered to the stock, according to my patent of 1857. To solder in the blades squares have to be heated, in most cases many times, to about 400 Fahrenheit, which is lia- .ble to change their form and crook them, so

that the accuracy sought after cannot be 6bthe blade and It will be readily seen that the longer the blade of a try-square the more difficnlt it must be to get it square. a p

In making a try-square of hardened steel in one form according to my improvement-say a thirty-six-inch square-the stock should be about twenty-two inches long, three wide, and one and a quarterthick; the blade thirty-nine inches long, four wide, and an eighth thick. The blade should be hardened at the edges, about three-sixteenths'of an inch wide,in any of the ways known for doing such work. The middle of the blade being soft, it can be trued by hammering and then ground flaton the sides and straight on the edges. The stock should be planed or ground true on the sides, edges,

and ends, and a gain made in the side of i one end about twice the thickness or the blade in depth, and about three inches long. Then a hole about five-eighths diameter should be made in the side of the stockin the middle of the gain, the lower partof the hole to be made transversely to-the stock.

' ing with the hole in the stock, a hollow bolt is .made to fill the hole in the stock and blade,

the bolt is split within a quarter of an inch of its wholelength,and theslot in the bolt stands A- tapering screw is titted to the interior of the bolt, by which it a little, as shown-at I in the drawings.

v The parts being thus 'COlllltlGtQd, to put the,

is expanded. The hole in'the stock is enlarged The hole in theblade is enlarged, as shown at J.

square together the bladeis placed in the gain and bolted firmlyto'the stock with the hollow vbolt.

Then the tapering central screw is screwed into-the hollow bolt as faras necess'ary to bring the edge of the,.blade firmly against the shoulderKin the stock and spring the stock slightly to produce anelastic press- :ure. After being thus put together, if the blade should not stand square with the stock it may be taken offend the shoulderK reground or: oilstoned to-make'it true. Theshoulder' K and thebladebeing so very hard, when once fitted will remain soa longtime. In a square ot'this size, if greater permanency is wanted thanthe double bolt ali'ords, common screws may 'beused in addition, as shown'in Fig. 3.

Figs. .4 and 5 show another method of putting together my improved square where the common screws are used, the holes in the stock between the screws and the shoulder ,K being enlarged-get little -say .001 inchas shown at I, and also the opposite side of the holes in theblade, as shown'atd. The screws have conical heads,as shown in Figs; 4 and 5,"

Then v or they may have flat heads, as shown in Fig.

7, taking care to have the screws bear against the blade to pressit against the shoulder in the handle sufficiently to produce a slight springof the stock. The holes in the blade are in the soft part, and the screws being soft, the bearings are liable to yield a little. Hence the necessity of having a spring reserve force to provide against accidents and hard usage.

Fig. (ishows the square blade put in the center of the stock and fastened with my double bolt. In thisv form the stock cannot-be sprung,

as it can be when the blade is put on the side,

and it is'more difficult to makeahard bearingfor the edge of the blade to bear against, and more difficult to adjust.-

Ha'vingdescribed my invention,whatIclaim is 1. A try-square consistingof the metal stock gained at one end to receive the metal blade, and having the blade secured thereto, substantially as described.

' 2. Atry-squarehavingitsmetalstock gained at one end, a steel blade, andthe double bolt by which the two are secured together, sub-.

stantially as described.

' 3. In combination with the steel stock of a try-square gained atone end and having a portion of its screw hole enlarged on the side toward the shoulder, the blade adapted to fit the gain, and having the hole i'or-th'e fasteningscrew enlargedion the sideaway from the shoulder, andan expansive bolt, all substantially as described, and for the purpose set forth.

4. The double bolt consistiitg of a. hollow bolt split at the head end and having an exterior and interior screw at the other end, and a.

centerpiece provided with a screw at one end, fitting the'lnternal screw of the hollow bolt for the purpose of expanding it, substantially as described.

SAML. DARLING. \Vitnessesi ;J A'ooB -KET1NER, JOHNE. HALL. 

